Stopper, Material Silicone, Product Type Stopper, Color Opaque, Autoclavable Yes, Special Features Stopper Ports Designed to Connect 1/8 in, 1/4 in (4-Port Stopper has Two 1/4 in Ports) and 3/8 in Silicone Tubing, Designed to Fit All Sizes of KIMAX(R) 14950 Solution (Carboy) Bottles, For Labware Type Bottles.